What Pistons are These? Have Lightning Bolt Stamp - See Pic

[Terbro]

I just bought an endoscope, and am trying to determine what pistons are in my motor. This is a photo of the screen of the camera, so it's extra grainy. These do not look forged to me, but could they be? Motor supposedly has less than 1K miles, and claimed to have forged pistons in it.

In "browsing" the piston with the endoscope, the piston looks nothing like a forged piston to me...looks very much like a cast piston, but I just want to confirm. And I'd like to know if the bolt = stock or what the scoop is there.

 

[forcefed3.8's]

Speed pro.

 

[scgnx2]

In "browsing" the piston with the endoscope, the piston looks nothing like a forged piston to me...looks very much like a cast piston, but I just want to confirm. And I'd like to know if the bolt = stock or what the scoop is there.[/QUOTE]

That looks like a "Speed Pro" logo.

 

[forcefed3.8's]

There might be a part number in the center of the dish.

 

[Terbro]

Does Speed Pro make cast pistons, or do they only make forged? I'm mainly interested to know whether it's a cast or forged piston. The relatively rough edges look cast to me.

 

[scgnx2]

Does Speed Pro make cast pistons, or do they only make forged? I'm mainly interested to know whether it's a cast or forged piston. The relatively rough edges look cast to me.

The only Speed Pro Pistons listed for Buick 231 v6 motors I've seen are pn# L2481F which are forged.

 

[earlbrown]

They make both cast and forged.

The only way to know if to either read the part number on the dish. Forged stats with L and cast starts with H.

-OR-

pop the oil drain out and look at the bottom of the piston.

 

[MAK507]

SEALED POWER hypereutectic piston. I use to have those. I got rid of them and got sealed power forged


Sent from my iPhone using Tapatalk

 

[Terbro]

SEALED POWER hypereutectic piston. I use to have those. I got rid of them and got sealed power forged

What's your confidence level? I got back in to look for a number and faintly saw what looked liked maybe a "636" on the dish. Not positive though.

 

[Terbro]

BTW, allegedly (again, unconfirmed) this motor was bored 0.020 over. So the pistons would've been sized accordingly. I do see hypereutectic pistons from Speed Pro here: http://www.summitracing.com/parts/slp-wh840cp50mm/overview/make/buick

 

[earlbrown]

It won't be .020" with speed pros. 30 over is the first jump from STD.

 

[Terbro]

It won't be .020" with speed pros. 30 over is the first jump from STD.

Now I'm really confused. The builder made it clear that he'd be boring it 0.020 over. But here's the thing. This is a well known person on this board, so I want to confirm that he's lied once again (I've already caught him scamming me on several other parts, including the transmission, fuel pump, torque convertor, and there's strong indication that I didn't get ported heads) before I post my story in the Feedback section. The TR community needs to be made aware...this is very important. So you're very confident about that...Speed Pro starts at 0.030 minimum?

 

[TurboBob]

It looks like the hypereutectics are/were available in .020

http://www.northernautoparts.com/part/sl-h521acp

Not sure how current this info is, I just googled for it.

 

[TURBOELKY]

Now I'm really confused. The builder made it clear that he'd be boring it 0.020 over. But here's the thing. This is a well known person on this board, so I want to confirm that he's lied once again (I've already caught him scamming me on several other parts, including the transmission, fuel pump, torque convertor, and there's strong indication that I didn't get ported heads) before I post my story in the Feedback section. The TR community needs to be made aware...this is very important. So you're very confident about that...Speed Pro starts at 0.030 minimum?

Why would you deal with someone who has already "scammed" you? This looks like it could get interesting, subscribing.

 

[Terbro]

Why would you deal with someone who has already "scammed" you? This looks like it could get interesting, subscribing.

No, it's not that he scammed me in the past...it's that I discovered other things he did as well when he built my motor and trans. This has been a long time brewing...I got the car back almost a year ago, and have had red flags since he received it over a year ago. I just posted the whole (long) story in the Feedback section: http://turbobuick.com/threads/nick-...-major-misconduct-beware.439376/#post-3655114

The piston issue is yet to be confirmed, and I will be fair about and post my findings once they're confirmed. I intend to be 100% fair and honest. I'm not out to bash...only to inform the TR Community.

 

[MAK507]

What's your confidence level? I got back in to look for a number and faintly saw what looked liked maybe a "636" on the dish. Not positive though.

TRW/Speed Pro/Federal Mogul/Sealed Power. All the same.


I'm positive. The hyper ones are far more common than the forged. Come to remember, the new ones I bought were .040 bore, hypereutectic... I did a lot of research on that material and the names those Pistons all go by and found nothing bad. These are the ones.. Found my invoice.

http://m.summitracing.com/parts/SLP-H521ACP40

Edit: P.S. These were suggested to me by Kenny Duttweiler himself. Face to face.

 

[earlbrown]

Don't get too excited about the crown indicating that they are cast. Hyper and forged are both lathe faced finishes. The logo is a seal power logo.

The only thing on the crown that will tell you want that slug is, is the part number. Otherwise you'll have to look at it from the bottom.

 

[TurboBob]

I believe there were .020 forged speed-pro's available at one time, so there are probably some sets floating around in the warehouses.

So a part number would be required, or a pic of the bottom side.

Bob

 

[Terbro]

TRW/Speed Pro/Federal Mogul/Sealed Power. All the same.


I'm positive. The hyper ones are far more common than the forged. Come to remember, the new ones I bought were .040 bore, hypereutectic... I did a lot of research on that material and the names those Pistons all go by and found nothing bad. These are the ones.. Found my invoice.

http://m.summitracing.com/parts/SLP-H521ACP40

Edit: P.S. These were suggested to me by Kenny Duttweiler himself. Face to face.

What is it exactly that makes you so sure? Not trying to grill you, just curious. I do want to be absolutely sure. One thing I've noticed that is the dish in the photos of the pistons I've seen, including the link that you've given me, looks a bit different than mine. On mine, that angle down to the basin of the dish is sharp (more like the curb on a sidewalk; 90 degree angle), whereas it's sloped/curved, i.e., "dish-like" in that link. Point being, the pistons I have look unique to anything I've seen so far.

If I have to drain the oil and put the endoscope up there, I will. But I'd rather not go through the trouble.

I did send a message to Speed Pro, with their form-field message system, explaining my goal. I've offered to send them the pic.

 

[pacecarta]

hypers have notches ...look again at what you have ..no notches and its forged
http://www.gnttype.org/techarea/pictureguides/pistonguide/38hyperpiston.html

forged
http://www.gnttype.org/techarea/pictureguides/pistonguide/38TRWforgedpiston.html